Aroma particles

ABSTRACT

The invention relates to vitreous aroma particles and the preparation thereof, as well as to the use thereof in foods, consumer articles and pharmaceuticals.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/561,798, filed Sep. 7, 2009, which is adivisional application of U.S. patent application Ser. No. 10/512,841,filed Apr. 1, 2005, which is a §371 national phase application ofPCT/EP2003/004383, filed Apr. 26, 2003, which claims priority to GermanPatent Application No. 10219228.6, filed Apr. 30, 2002, all of which areincorporated herein by reference.

SUMMARY OF THE INVENTION

The invention relates to vitreous aroma particles and the preparationthereof, as well as to the use thereof in food products, consumerarticles and pharmaceuticals.

In the present invention, an aroma is understood to be a substance whichbrings about odour impressions and/or flavour impressions. It can beconstituted here by individual substances or individual materials, or bymixtures. An aroma is also understood to be olfactory substances, aromasubstances, flavour substances, perfume oils, fragrances, olfactorysubstance compositions, fragrance mixtures and the like.

Aroma particles (encapsulated aroma) are understood in the presentinvention to be encapsulations which comprise the encapsulating material(the matrix) and an aroma. The matrices mentioned hereinbelow arevitreous and are also described as glasses.

Aromas are generally highly complex mixtures, that is to saycombinations of many chemical substances having different chemical andphysical properties. As the need for stable products in a very widevariety of applications such as food products, consumer articles andpharmaceuticals increases, there is a growing need for encapsulation ofsuch aromas.

The best possible protection in the matrix, or the maximum durability,is generally sought.

Aroma losses during encapsulation should be minimised and aromaretention during storage maximised. Above and beyond this, for aromautilisation to be cost-effective for the user a high payload plus highretention of the volatile aromas are important. Retrieval in theencapsulated product of those aroma substances utilised by way of therecipe is described as “retention”.

A further aim is a freely adjustable particle size within the range 0.1to 5 mm, with a narrow size distribution. A virtually spherical productor a cylindrical product having a diameter:length ratio close to 1 issought.

Encapsulated aromas having particularly good stability in storage aregenerally prepared in the aroma industry by emulsification of the aromain molten carbohydrate mixtures, followed by forming or comminution.Older processes (for example U.S. Pat. No. 4,707,367, U.S. Pat. No.4,499,112) operate in batch-wise manner with stirred tanks. Morerecently, a continuous procedure in twin-screw extruders has proved tobe particularly advantageous (for example U.S. Pat. No. 5,603,971, WO94/06308, U.S. Pat. No. 5,009,900).

In extrusion, continuous cylindrical strands are first obtained whereofthe diameter is determined by the diameter of the drilled holes of theperforated disk which is used. As a result of comminution in adownstream mechanical comminution process (for example a pelletiser orcrusher), the continuous strand is divided into cylindrical sections. Ifthe strand diameter exceeds the desired final diameter, the strand mustbe broken additionally in the direction of its axis.

At all events, the comminution step destroys the surface structure ofthe particles. A disadvantage associated with this is an elevatedloading with an oily layer of the aroma which is utilised. The oilylayer of the aroma which is utilised, which is on the surface causes theparticles to adhere, as well as greatly impairing the stability of theparticles in storage. An undesirably high proportion of fine dust is,moreover, formed.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,820,534 discloses a method for fixing labile substancessuch as, for example, essential oils in an extruded glass, characterisedin that the quantitatively more important component present in aproportion by weight of at least 70% is a maltodextrin having a DE(dextrose equivalent) of up to 20. The resulting matrix is a hard,non-hygroscopic glass from which encapsulated essential oils or otheraromas can be prepared without the addition of emulsifiers and flowpromoting agents. In order to obtain small particle sizes, in particularparticles smaller than 1 mm, coarse strands must first be prepared whichare subsequently comminuted and sieved in a labour-intensive process, asa result of which undesirable dusty fines arise. A direct processing ofthis glass by way of perforated disks having small openings (smallerthan 1 mm) is not possible because, at the necessary temperatures,undesirable aroma losses and aroma reactions, as well as carbonisationand blockages in the extruder, would result.

U.S. Pat. No. 5,972,395 discloses the use of a quantitativelysubordinate proportion by weight, of from 15 to 30%, of the maltodextrinhaving a dextrose equivalent of up to 20. The encapsulation ofwater-insoluble lipophilic fish oil or of solid labile components suchas carotene and maltol is described. These materials have only a slightplasticising effect on the matrix. This method cannot, however, beapplied to the encapsulation of commercial aromas because practicallyall natural, nature-identical or artificial aromas contain componentswhich act as highly effective plasticisers of the carbohydrate matrixaccording to U.S. Pat. No. 5,972,395, as a result of which the glassbecomes sticky and difficult to process.

Very hard glasses make processing difficult on account of their highmelt viscosity, such that flow through small openings is no longerpossible. Soft matrices are impossible, or difficult, to process by wayof melt extrusion and integrated comminution because the melt is toosoft and the particles formed tend to adhere. This problem occurs inparticular when the melt is discharged through small openings. Inaddition, soft glasses can result in undesirably large drops of thearoma in the matrix and hence even in efflux of the aroma in liquidform.

Carbohydrate matrices and processes for the preparation thereof aretherefore sought which enable aromas to be encapsulated in a stablemanner by means of melt extrusion and die-face pelletisation, while nothaving the disadvantages of the prior art which have been described. Inthe present invention, die-face pelletisation is understood to be acomminution, directly at the extruder exit, of the melt discharged fromthe extruder. The still soft surface structure is sealed by the actionof the die-face pelletisation.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides vitreous aroma particles prepared byextrusion of an aromatised melt, followed by die-face pelletisation,characterised in that the matrix of the particles contains from 20 to 80wt. %, preferably 30 to 70 wt. %, particularly preferably 40 to 60 wt.%, carbohydrate polymers having an average molecular weight greater than1000, the aromatised melt is discharged from the extruder by way of anopening and is comminuted in the still unsolidified state.

The present invention also provides a process for the preparation of thearoma particles according to the invention, as well as the use thereofin foods, pharmaceuticals and consumer articles.

The carbohydrate polymers used are prepared by acid or enzymatichydrolysis of starch. Starch is a long-chain glucose polymer.

Complete acid hydrolysis of starch results in glucose. In enzymatichydrolysis of starch the glucose dimer, maltose, can also be produced.The characteristic value by which the degree of decomposition of thestarch is measured is the “dextrose equivalent” (DE), which can take thelimit values 0 for the long-chain glucose polymer and 100 for the pureglucose. The water-solubility of the starch degradation productsincreases as the DE value increases. Starch degradation products havinga DE of less than 10 are sparingly soluble in water.

According to a rough formula known from the literature (H. Levine, L.Slade: “Water as a plasticizer: physico-chemical aspects of low moisturepolymeric systems”, in Water Science Reviews, 1988, Vol. 3, F. Franks(Ed.), pp. 79-185, Cambridge University Press, Cambridge, England), theaverage molecular weight of the starch degradation products is inverselyproportional to the DE value: 1 average molecular weight=18016 DE

All the data which follow relating to the average molecular weight ofthe starch degradation products are obtained by way of this roughformula. It should be pointed out at this point that other methods ofdetermining the molecular weights (for example gel chromatography orcalorimetry) may possibly lead to widely diverging results.

Now, when the starch decomposes (DE markedly less than 10, averagemolecular weight far above 2000) maltodextrins (DE 10 to 20, averagemolecular weight 1000 to 2000) arise initially, which can be degradedfurther to glucose syrups (DE>20, average molecular weight less than1000) comprising monomeric sugars.

Maltodextrins substantially comprise polymers having a degree ofpolymerisation (degree of polymerisation DP) of the glucose starting at4 (maltotetraose, molecular weight 720) and above. They contain onlysmaller quantities of monomeric sugars such as glucose (DP 1, molecularweight 180.2), maltose (DP 2, molecular weight 360.4) and maltotriose(DP 3, molecular weight 540.6).

In a preferred embodiment maltodextrins having dextrose equivalentswithin the range 10 to 20 may be used. Maltodextrins having a DE of 15to 19 are particularly preferred. Here, the plant which originallysupplied the starch for the preparation of the starch hydrolysates isimmaterial. Maize-based raw materials are suitable and readilyavailable, in order to guarantee a product that is free from geneticallymodified constituents raw materials from tapioca, rice, wheat, potatoescan, for example, also be utilised.

Maltodextrins increase the binding of aromas in the matrix. Thecarbohydrate polymers have melting points greater than 190° C.,preferably greater than 200° C. The carbohydrate polymers used haveglass transition temperatures of over 70° C., preferably over 80° C., inparticular preferably over 90° C.

The proportion of from 70 to 30 wt. %, which is complementary to thecarbohydrate polymer content of 30 to 70 wt. %, embraces water-soluble,low molecular weight compounds having molecular weights within the range90 to 950 and a melting point within the range 80° C. to 180° C.

Suitable water-soluble, low molecular weight compounds are, for example,monosaccharides, disaccharides and trisaccharides, sugar alcohols, solidfood acids or mixtures thereof. Particularly suitable monosaccharides,disaccharides and trisaccharides are, for example, arabinose, xylose,fructose, galactose, glucose, mannose, sorbose, lactose, maltose,saccharose, maltotriose.

Particularly suitable sugar alcohols are, for example, mannitol,sorbitol, xylitol, arabinol, arabitol, adonitol, alditol, ducitol,iditol.

Particularly suitable food acids are, for example, citric acid, adipicacid, malic acid, fumaric acid, succinic acid, lactic acid, benzoicacid.

If there exist isomers of the named compounds, the pure isomers or anymixtures thereof may be used.

The matrix of the particles preferably additionally contains anemulsifier. The additional incorporation of a small quantity, from 0.5to 3 wt. %, of monoglycerides (a specific class of emulsifiers) into thematrix is advantageous in order to facilitate flow of the melt throughopenings (for example of a pelletising die) less than 1.0 mm in size.

Decaglycerol dipalmitate, hexaglycerol distearate, polyglycerol esters,sulfoacetates, lecithin are also suitable as emulsifiers.

It has also been found that a minimum quantity of glucose in the matrixenables die-face pelletisation to take place without the undesirableformation of fines and without adhesion of the freshly formed particles.A glucose content of from 0.5 to 5 wt. % in the matrix is particularlypreferred.

The use of maltotriose, which can improve holding-back of the aroma,thus making possible a higher aroma payload, is furthermoreadvantageous. If, with a higher aroma payload, a greater proportion ofthe undesirable oily layer of the aroma utilised, which arises duringcomminution, should occur, a convective treatment with inert gas (forexample nitrogen, noble gases, air) can be effected in order to removethis oily layer.

The water-soluble low molecular weight compounds reduce the softeningpoint of the matrix: the higher the proportion thereof in the mixture,the more readily the matrix can be melted. The processing temperature isreduced thereby. The product strands are, however, more difficult tocut, and the pellets are less stable to humidity and temperature. Thelow molecular weight compounds additionally facilitate pelletisation atthe pelletising dies. The product becomes glass-hard more rapidly. If,however, excessive quantities of low molecular weight compounds areutilised the product already adheres at the pelletising die. In storagetoo, increased sticking occurs.

The aroma particles according to the invention typically have a glasstransition temperature within the range 30 to 100° C., preferably withinthe range 45 to 75° C., particularly preferably within the range 50 to60° C. The glass transition temperatures were obtained by means ofdifferential scanning calorimetry (DSC, heating rate 20 K/min).

The aroma particles preferably have a cylindrical or spherical geometryand a narrow particle size profile. They have a diameter of from 0.1 to5 mm, preferably 0.2 to 2.5 mm, in particular preferably 0.3 to 1.5 mm,and a length of from 0.1 to 10 mm, preferably 0.2 to 3.0 mm, inparticular preferably 0.3 to 1.5 mm.

The aroma particles according to the invention are highly stable instorage. The aroma particles according to the invention are on thesurface practically free from any oily layer of the aroma which isutilised. The aroma is practically exclusively in the interior of theparticles. If necessary, flow promoting agents may be added to the aromaparticles in order to reduce still further the stickiness of the matrix.

The aroma particles according to the invention have an aroma content offrom 0.5 to 25 wt. %, preferably 1 to 20 wt. %, in particular preferably3 to 15 wt. %, in relation to the total weight of aroma particles.

Examples of olfactory substances which may be a constituent of thearoma, are found, for example, in S. Arctander, Perfume and FlavorMaterials, Vols. I and II, Montclair, N.J., 1969, published by theauthor, or K. Bauer, D. Garbe and H. Surburg, Common Fragrance andFlavor Materials, 3^(rd) Edition, Wiley-VCH, Weinheim 1997.

The following might be named individually: extracts from natural rawmaterials such as essential oils, concretes, absolutes, resins,resinoids, balsams, tinctures such as, for example, ambergris tincture;amyris oil, angelica seed oil; angelica root oil; aniseed oil; valerianoil, basil oil; tree moss absolute; bay oil; mugwort oil; benzoin resin;bergamot oil; beeswax absolute; birch tar oil; bitter almond oil; savoryoil; buchu leaf oil; cabreuva oil; cade oil; calmus oil; camphor oil;cananga oil; cardamom oil; cascarilla oil; cassia oil; cassia absolute;castoreum absolute; cedar leaf oil; cedar wood oil; cistus oil;citronella oil; lemon oil; copaiba balsam; copaiba balsam oil; corianderoil: costus root oil; cumin oil; cypress oil; davana oil; dill herb oil;dill seed oil; eau de brouts absolute; oak moss absolute; elemi oil;tarragon oil; eucalyptus citriodora oil; eucalyptus oil; fennel oil;fir-needle oil; galbanum oil; galbanum resin; geranium oil; grapefruitoil; guaiac wood oil; gurjun balsam; gurjun balsam oil; helichrysumabsolute; helichrysum oil; ginger oil; iris root absolute; iris rootoil; jasmine absolute; calmus oil; camomile oil, blue; camomile oil,Roman; carrot seed oil; cascarilla oil; pine-needle oil; spearmint oil;caraway oil; labdanum oil; labdanum absolute; labdanum resin; lavandinabsolute; lavandin oil; lavender absolute; lavender oil; lemongrass oil;lovage oil; lime oil, distilled; lime oil, pressed; linaloe oil; Litseacubeba oil; laurel leaf oil; mace oil; marjoram oil; mandarin oil;massoia bark oil; mimosa absolute; ambrette seed oil; musk tincture;clary sage oil; nutmeg oil; myrrh absolute; myrrh oil; myrtle oil; cloveleaf oil; clove flower oil; neroli oil; frankincense absolute;frankincense oil; opopanax oil; orange flower absolute; orange oil;origanum oil; palmarosa oil; patchouli oil; perilla oil; Peruvian balsamoil; parsley leaf oil; parsley seed oil; petitgrain oil; peppermint oil;pepper oil; pimento oil; pine oil; pennyroyal oil; rose absolute;rosewood oil; rose oil; rosemary oil; sage oil, Dalmation; sage oil,Spanish; sandalwood oil; celery seed oil; spike lavender oil; star aniseoil; styrax oil; tagetes oil; fir-needle oil; tea tree oil; terpentineoil; thyme oil; Tolu balsam; tonka absolute; tuberose absolute; vanillaextract; violet leaf absolute; verbena oil; vetiver oil; juniper oil;wine lees oil; absinthe oil; wintergreen oil; ylang oil; hyssop oil;civet absolute; cinnamon leaf oil; cinnamon bark oil; as well asfractions thereof, and constituent substances isolated therefrom;

Individual olfactory substances from the group of hydrocarbons such as,for example, 3-carene; α-pinene; β-pinene; α-terpinene, γ-terpinene,p-cymene; bisabolene; camphene; caryophyllene; cedrene; farnesene;limonene; longifolene; myrcene; ocimene; valencene;(E,Z)-1,3,5-undecatriene;

of aliphatic alcohols such as, for example, hexanol; octanol; 3-octanol;2,6-dimethylheptanol; 2-methylheptanol, 2-methyloctanol; (E)-2-hexenol;(E)- and (Z)-3-hexenol; 1-octen-3-ol; mixture of3,4,5,6,6-pentamethyl-3/4-hepten-2-ol and3,5,6,6-tetramethyl-4-methylene-heptan-2-ol; (E,Z)-2,6-nonadienol;3,7-dimethyl-7-methoxyoctan-2-ol; 9-decenol; 10-undecenol;4-methyl-3-decen-5-ol; of aliphatic aldehydes and1,4-dioxacycloalken-2-ones thereof, such as, for example, hexanal;heptanal; octanal; nonanal; decanal; undecanal; dodecanal; tridecanal;2-methyloctanal; 2-methylnonanal; (E)-2-hexenal; (Z)-4-heptenal;2,6-dimethyl-5-heptenal; 10-undecenal; (E)-4-decenal; 2-dodecenal;2,6,10-trimethyl-5,9-undecadienal; heptanal diethylacetal;1,1-dimethoxy-2,2,5-trimethyl-4-hexene; citronellyl oxyacetaldehyde;of aliphatic ketones and oximes thereof, such as, for example,2-heptanone; 2-octanone; 3-octanone; 2-nonanone; 5-methyl-3-heptanone;5-methyl-3-heptanone oxime; 2,4,4,7-tetramethyl-6-octen-3-one; ofaliphatic sulfur-containing compounds such as, for example,3-methylthiohexanol; 3-methylthiohexyl acetate; 3-mercaptohexanol;3-mercaptohexyl acetate; 3-mercaptohexyl butyrate; 3-acetylthiohexylacetate; 1-menthene-8-thiol.of aliphatic nitriles such as, for example, 2-nonene nitrile;2-tridecene nitrile; 2,12-tridecadiene nitrile;3,7-dimethyl-2,6-octadien-e nitrile; 3,7-dimethyl-6-octene nitrile;of aliphatic carboxylic acids and esters thereof such as, for example,(E)- and (Z)-3-hexanyl formate; ethyl acetoacetate; isoamyl acetate;hexyl acetate; 3,5,5-trimethylhexyl acetate; 3-methyl-2-butenyl acetate;(E)-2-hexenyl acetate; (E)- and (Z)-3-hexenyl acetate; octyl acetate;3-octyl acetate; 1-octen-3-yl acetate; ethyl butyrate; butyl butyrate;isoamyl butyrate; hexyl butyrate; (E)- and (Z)-3-hexenyl isobutyrate;hexyl crotonate; ethyl isovalerate; ethyl-3-methylpentanoate-; ethylhexanoate; allyl hexanoate; ethyl heptanoate; allyl heptanoate; ethyloctanoate; ethyl-(E,Z)-2,4-decadienoate; methyl-2-octynoate;methyl-2-nonynoate; allyl-2-isoamyl oxyacetate;methyl-3,7-dimethyl-2,6-o-ctadienoate;of acyclic terpene alcohols such as, for example, citronellol; geraniol;nerol; linalool; lavandulol; nerolidol; farnesol; tetrahydrolinalool;tetrahydrogeraniol; 2,6-dimethyl-7-octen-2-ol; 2,6-dimethyloctan-2-ol;2-methyl-6-methylene-7-octen-2-ol; 2,6-dimethyl-5,7-octadien-2-ol;2,6-dimethyl-3,5-octadien-2-ol; 3,7-dimethyl-4,6-octadien-3-ol;3,7-dimethyl-1,5,7-octatrien-3-ol; 2,6-dimethyl-2,5,7-octatrien-1-ol; aswell as formates, acetates, propionates, isobutyrates, butyrates,isovalerates, pentanoates, hexanoates, crotonates, tiglinates,3-methyl-2-butenoates thereof;

of acyclic terpene aldehydes and acyclic terpene ketones, such as, forexample, geranial; neral; citronellal; 7-hydroxy-3,7-dimethyloctanal;7-methoxy-3,7-dimethyloctanal; 2,6,10-trimethyl-9-undecenal; geranylacetone; as well as the dimethyl and diethyl acetals of geranial, neral,7-hydroxy-3,7-dimethyloctanal;

of cyclic terpene alcohols such as, for example, menthol; isopulegol;alpha-terpineol; terpinenol-4; menthan-8-ol; menthan-1-ol; menthan-7-ol;borneol; isoborneol; linalool oxide; nopol; cedrol; ambrinol; vetiverol;guaiol; as well as formates, acetates, propionates, isobutyrates,butyrates, isovalerates, pentanoates, hexanoates, crotonates,tiglinates, 3-methyl-2-butenoates thereof;

of cyclic terpene aldehydes, and cyclic terpene ketones, such as, forexample, menthone; isomenthone; 8-mercaptomenthan-3-one; carvone;camphor; fenchone; alpha-ionone; beta-ionone; alpha-n-methylionone;beta-n-methylionone; alpha-isomethylionone; beta-isomethylionone;alpha-irone; alpha-damascone; beta-damascone; beta-damascenone;delta-damascone; gamma-damascone;1-(2,4,4-trimethyl-2-cyclohexen-1-yl)-2-buten-1-one;1,3,4,6,7,8a-hexahydro-1,1,5,5-tetramethyl-2H-2,4-a-methanona-phthalen-8(5H)-one;nootkatone; dihydronootkatone; alpha-sinensal; beta-sinensal; acetylatedcedar wood oil (methyl cedryl ketone);

of cyclic alcohols such as, for example, 4-tert.-butylcyclohexanol;3,3,5-trimethylcyclohexanol; 3-isocamphylcyclohexanol;2,6,9-trimethyl-Z2,Z5,E9-cyclododecatrien-1-ol;2-isobutyl-4-methyltetrah-ydro-2H-pyran-4-ol;

of cycloaliphatic alcohols such as, for example,alpha,3,3-trimethylcyclohexylmethanol;2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)butanol;2-methyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol;2-ethyl-4-(2,2,3-trimethyl-3-cyclopent-1-yl)-2-buten-1-ol;3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)pentan-2-ol;3-methyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol;3,3-dimethyl-5-(2,2,3-trimethyl-3-cyclopent-1-yl)-4-penten-2-ol;1-(2,2,6-trimethylcyclohexyl)pentan-3-ol;1-(2,2,6-trimethylcyclohexyl)he-xan-3-ol;

of cyclic and cycloaliphatic ethers, such as, for example, cineole,cedryl methyl ether; cyclododecyl methyl ether;(ethoxymethoxy)cyclododec-ane; alpha-cedrene epoxide;3a-6,6,9a-tetramethyldodecahydronaphtho[2,1-b]-furan;3a-ethyl-6,6,9a-trimethyldodecahydronaptho[2,1-b]furan;1,5,9-trimethyl-13-oxabicyclo[10.1.0]trideca-4,8-diene; rose oxide;2-(2,4-dimethyl-3-cyclohexen-1-yl)-5-methyl-5-(1-methylpropyl)-1,3-dioxan-e;of cyclic ketones such as, for example, 4-tert.-butylcyclohexanone;2,2,5-trimethyl-5-pentylcyclopentanone; 2-heptylcyclopentanone;2-pentylcyclopentanone; 2-hydroxy-3-methyl-2-cyclopenten-1-one;3-methyl-cis-2-penten-1-yl-2-cyclopenten-1-one;3-methyl-2-pentyl-2-cyclo-penten-1-one; 3-methyl-4-cyclopentadecenone;3-methyl-5-cyclopentadecenone-; 3-methylcyclopentadecanone;4-(1-ethoxyvinyl)-3,3,5,5-tetramethylcyclohe-xanone;4-tert.-pentylcyclohexanone; 5-cyclohexadecen-1-one;6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone;5-cyclohexadecen-1-one; 8-cyclohexadecen-1-one, 9-cycloheptadecen-1-one;cyclopentadecanone;of cycloaliphatic aldehydes such as, for example,2,4-dimethyl-3-cyclohexene carbaldehyde;2-methyl-4-(2,2,6-trimethylcyclo-hexen-1-yl)-2-butenal;4-(4-hydroxy-4-methylpentyl)-3-cyclohexene carbaldehyde;4-(4-methyl-3-penten-1-yl)-3-cyclohexene carbaldehyde;of cycloaliphatic ketones such as, for example,1-(3,3-dimethylcyclohexyl)-4-penten-1-one;1-(5,5-dimethyl-1-cyclohexen-1-yl)-4-penten-1-one;2,3,8,8-tetramethyl-1,2,3,4,5,6,7,8-octahydro-2-napht-halenyl methylketone; methyl-2,6,10-trimethyl-2,5,9-cyclododecatrienyl ketone;tert.-butyl-(2,4-dimethyl-3-cyclohexen-1-yl)ketone;of esters of cyclic alcohols, such as, for example,2-tert.-butylcyclohexyl acetate; 4-tert.-butylcyclohexyl acetate;2-tert.-pentylcyclohexyl acetate; 4-tert.-pentylcyclohexyl acetate;decahydro-2-naphthyl acetate; 3-pentyltetrahydro-2H-pyran-4-yl acetate;decahydro-2,5,5,8a-tetramethyl-2-naphthyl acetate;4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl acetate;4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl propionate;4,7-methano-3a,4,5,6,7,7a-hexahydro-5 or 6-indenyl isobutyrate;4,7-methanooctahydro-5 or 6-indenyl acetate;of esters of cycloaliphatic carboxylic acids, such as, for example,allyl-3-cyclohexyl propionate; allyl cyclohexyloxyacetate; methyldihydrojasmonate; methyl jasmonate; methyl-2-hexyl-3-oxocyclopentanecarboxylate; ethyl-2-ethyl-6,6-dimethyl-2-cyclohexenecarboxylate;ethyl-2,3,6,6-tetramethyl-2-cyclohexene carboxylate;ethyl-2-methyl-1,3-dioxolan-2-acetate;of aromatic hydrocarbons such as, for example, styrene anddiphenylmethane;of araliphatic alcohols such as, for example, benzyl alcohol;1-phenylethyl alcohol; 2-phenylethyl alcohol; 3-phenylpropanol;2-phenylpropanol; 2-phenoxyethanol; 2,2-dimethyl-3-phenylpropanol;2,2-dimethyl-3-(3-methylphenyl) propanol; 1,1-dimethyl-2-phenylethylalcohol; 1,1-dimethyl-3-phenylpropanol;1-ethyl-1-methyl-3-phenylpropanol-; 2-methyl-5-phenylpentanol;3-methyl-5-phenylpentanol; 3-phenyl-2-propen-1-ol; 4-methoxybenzylalcohol; 1-(4-isopropylphenyl)eth-anol;of esters of araliphatic alcohols and aliphatic carboxylic acids, suchas, for example; benzyl acetate; benzyl propionate; benzyl isobutyrate;benzyl isovalerate; 2-phenylethyl acetate; 2-phenylethyl propionate;2-phenylethyl isobutyrate; 2-phenylethyl isovalerate; 1-phenylethylacetate; alpha-trichloromethylbenzyl acetate;alpha,alpha-dimethylphenylethyl acetate; alpha-alpha-dimethylphenylethylbutyrate; cinnamyl acetate; 2-phenoxyethyl isobutyrate; 4-methoxybenzylacetate; of araliphatic ethers such as, for example, 2-phenylethylmethyl ether; 2-phenylethyl isoamyl ether; 2-phenylethyl-1-ethoxyethylether; phenylacetaldehyde dimethyl acetal; phenylacetaldehyde dietheylacetal; hydratropaldehyde dimethyl acetal; phenylacetaldehyde glycerolacetal; 2,4,6-trimethyl-4-phenyl-1,3-dioxane;4,4a,5,9b-tetrahydroindeno[1,2-d]-m-dioxin;4,4a,5,9b-tetrahydro-2,4-dimethylindeno[1,2-d]-m-dioxin; of aromatic andaraliphatic aldehydes, such as, for example, benzaldehyde; phenylacetaldehyde; 3-phenylpropanal; hydratropaldehyde; 4-methylbenzaldehyde;4-methylphenyl acetaldehyde; 3-(4-ethylphenyl)-2,2-dimethylpropanal;2-methyl-3-(4-isopropylphenyl)pro-panal;2-methyl-3-(4-tert.-butylphenyl)propanal; 3-(4-tert.-butylphenyl)propanal; cinnamaldehyde; alpha-butylcinnamaldehyde;alpha-amylcinnamaldehyde; alpha-hexylcinnamaldehyde;3-methyl-5-phenylpentanal; 4-methoxybenzaldehyde;4-hydroxy-3-methoxybenz-aldehyde; 4-hydroxy-3-ethoxybenzaldehyde;3,4-methylenedioxybenzaldehyde; 3,4-dimethoxybenzaldehyde;2-methyl-3-(4-methoxyphenyl)-propanal;2-methyl-3-(4-methylenedioxyphenyl)propanal;of aromatic and araliphatic ketones, such as, for example, acetophenone;4-methylacetophenone; 4-methoxyacetophenone;4-tert.-butyl-2,6-dimethylacetophenone; 4-phenyl-2-butanone;4-(4-hydroxyphenyl)-2-butanone; 1-(2-naphthalenyl)ethanone;benzophenone; 1,1,2,3,3,6-hexamethyl-5-indanyl methyl ketone:6-tert.-butyl-1,1-dimethyl-l-4-indanyl methyl ketone;1-[2,3-dihydro-1,1,2,6-tetramethyl-3-(1-methyle-thyl)-1H-5-indenyl]ethanone;5′,6′,7′,8′-tetrahydro-3′,5′,5′,6′,8′,8′-hexamethyl-2-acetonaphthone;of aromatic and araliphatic carboxylic acids and esters thereof, suchas, for example, benzoic acid; phenylacetic acid, methyl benzoate; ethylbenzoate; hexyl benzoate; benzyl benzoate; methyl phenyl acetate; ethylphenyl acetate; geranyl phenyl acetate; phenyl ethyl phenylacetate;methyl cinnamate; ethyl cinnamate; benzyl cinnamate; phenylethylcinnamate; cinnamyl cinnamate; allyl phenoxyacetate; methyl salicylate;isoamyl salicylate; hexyl salicylate; cyclohexyl salicylate;cis-3-hexenyl salicylate; benzyl salicylate; phenylethyl salicylate;methyl-2,4-dihydroxy-3,6-dimethylbenzoate; ethyl-3-phenylglycidate;ethyl-3-methyl-3-phenylglycidate;of nitrogen-containing aromatic compounds such as, for example,2,4,6-trinitro-1,3-dimethyl-5-tert.-butylbenzene;3,5-dinitro-2,6-dimethyl-l-4-tert.-butylacetophenone; cinnamonitrile;5-phenyl-3-methyl-2-pentene nitrile; 5-phenyl-3-methylpentane nitrile;methyl anthranilate; methyl-N-methyl anthranilate; Schiff's bases ofmethyl anthranilate with 7-hydroxy-3,7-dimethyl octanal,2-methyl-3-(4-tert.-butylphenyl)propanal or2,4-dimethyl-3-cyclohexenecarbaldehyde; 6-isopropylquinoline;6-isobutylquinoline; 6-sec.-butylquinoline; indole; skatole;2-methoxy-3-isopropylpyrazine; 2-isobutyl-3-methoxypyrazine;of phenols, phenyl ethers and phenyl esters, such as, for example,estragole; anethole; eugenol; methyl eugenol; isoeugenol; methylisoeugenol; thymol; carvacrol; diphenyl ether; beta-naphthyl methylether; beta-naphthyl ethyl ether; beta-naphthyl isobutyl ether;1,4-dimethoxybenzene; eugenyl acetate; 2-methoxy-4-methylphenol;2-ethoxy-5-(1-propenyl) phenol; p-cresylphenyl acetate;of heterocyclic compounds such as, for example,2,5-dimethyl-4-hydroxy-2H-furan-3-one;2-ethyl-4-hydroxy-5-methyl-2H-fura-n-3-one;3-hydroxy-2-methyl-4H-pyran-4-one; 2-ethyl-3-hydroxy-4H-pyran-4-o-ne;of lactones such as, for example, 1,4-octanolide;3-methyl-1,4-octanolide; 1,4-nonanolide; 1,4-decanolide;8-decen-1,4-olide; 1,4-undecanolide; 1,4-dodecanolide; 1,5-decanolide;1,5-dodecanolide; 1,15-pentadecanolide; cis- andtrans-11-pentadecen-1,15-olide; cis- and trans-12-pentadecen-1,15-olide;1,16-hexadecanolide; 9-hexadecen-1,16-olide; 10-oxa-1,16-hexadecanolide;11-oxa-1,16-hexadecanolide; 12-oxa-1,16-hexadecanolide;ethylene-1,12-dodecanedioate; ethylene-1,13-tridecanedioate; coumarin;2,3-dihydrocoumarin; octahydrocoumarin; Examples of flavour substanceswhich may be a constituent of the aroma are, in addition to all theaforementioned substances, primarily the following substances classes:aliphatic esters (saturated and unsaturated), for example ethylbutyrate, allyl capronate; aromatic esters, for example benzyl acetate,methyl salicylate; organic aliphatic acids (saturated and unsaturated),for example butyric acid, ethanoic acid, hexanoic acid; organic aromaticacids; aliphatic alcohols (saturated and unsaturated), for exampleethanol, propylene glycol, octenol; cyclic alcohols, for examplementhol; aromatic alcohols, for example benzyl alcohol; aliphaticaldehydes (saturated and unsaturated), for example acetaldehyde,nonadienal; aromatic aldehydes, for example benzaldehyde; ketones, forexample menthone; cyclic ethers, for example 4-hydroxy-5-methylfuranone;aromatic ethers, for example p-methoxybenzaldehyde; guaiacol; phenolicethers, for example methoxyvinyl phenol; acetals, for exampleacetaldehyde diethyl acetal; lactones, for example γ-decalactone;terpenes, for example, limonene, linalool, terpinene, terpineol, citral(geranial and neral); sulfides, for example dimethyl sulfide; thiols,for example methylfuran thiol; disulfides, for example difurfuryldisulfide; pyrazines, for example methylpyrazine, acetyl pyrazine.

The aroma particles may contain substances or substance mixtures, whichare active in nutritional physiology (neutriceuticals). The followingmight be named by way of example: panthenol, pantothenic acid, essentialfatty acids, vitamin A and derivatives, carotenes, vitamin C (ascorbicacid), vitamin E (tocopherol) and derivatives, vitamins of the B and Dseries, such as vitamin B₆ (nicotinamide), vitamin B₁₂, vitamin D₁,vitamin D₃, vitamin F, folic acid, biotin, amino acids, compounds of theelements magnesium, silicon, phosphorus, calcium, manganese, iron orcopper, coenzyme Q10, unsaturated fatty acids, ω-3-fatty acids,polyunsaturated fatty acids, γ-linolenic acid, oleic acid,eicosapentaenoic acid, docosahexaenoic acid and derivatives thereof,bisabolene, chloramphenicol, caffeine, capsaicin, prostaglandins,thymol, camphor, extracts or other products of plant and animal origin,for example evening primrose oil, borage oil or blackcurrant seed oil,fish oils, fish-liver oil, ceramides and ceramide-like compounds, plantextracts such as, for example, arnica, aloe, beard lichen, ivy, nettle,ginseng, henna, camomile, calendula, rosemary, sage, equisetum or thyme.Oils such as apricot kernel oil, avocado oil, babassu oil, cottonseedoil, borage oil, thistle oil, groundnut oil, gamma-oryzanol, rose-hipseed oil, hemp oil, hazelnut oil, blackcurrant seed oil, jojoba oil,cherry kernel oil, salmon oil, linseed oil, maize germ oil, macadamianut oil, almond oil, evening primrose oil, mink fat, olive oil, pecannut oil, peach kernel oil, pistachio nut oil, rape-seed oil, rice germoil, castor oil, safflower seed oil, sesame seed oil, soybean oil,sunflower seed oil, tea tree oil, grape-seed oil or wheat germ oil.

It is of course possible for the aroma particles according to theinvention to contain additionally other substances such as, for example,emulsifiers, colorants, antioxidants, stabilisers, UV-filters, vitaminsand other ingredients which are conventional in the food, cosmetics orolfactory substance industries.

Suitable antioxidants are, for example, amino acids (for example,glycin, histidine, tyrosine, tryptophan) and derivatives thereof,imidazoles (for example urocanic acid) and derivatives thereof, peptidessuch as D,L-carnosine, D-carnosine, L-carnosine and derivatives thereof(for example anserine), carotinoids, carotenes (for example α-carotene,β-carotene, lycopene) and derivatives thereof, lipoic acid andderivatives thereof (for example dihydro-α-lipoic acid),aurothioglucose, propyl thiouracil and other thiols (for examplethioredoxin, glutathione, cysteine, cystine, cystamine and glycosyl,N-acetyl, methyl, ethyl, propyl, amyl, butyl and lauryl, palmitoyl,oleyl, γ-linoelyl, cholesteryl, glyceryl and olioglyceryl estersthereof) as well as salts thereof, dilauryl thiodipropionate, distearylthiodipropionate, thiodipropionic acid and derivatives thereof (esters,ethers, peptides, lipids, nucleotides, nucleosides and salts) as well assulfoximine compounds (for example buthionine sulfoximines, homocysteinesulfoximine, buthionine sulfones, penta-, hexa-, heptathioninesulfoximine) in very small compatible doses (for example pmol to.mu.mol/kg), furthermore (metal) chelating agents (for example α-hydroxyfatty acids, palmitic acid, phytic acid, lactoferrin), α-hydroxy acids(for example citric acid, lactic acid, malic acid), humic acid, bileacid, bile extracts, bilirubin, biliverdin, EDTA, EGTA and derivativesthereof, unsaturated fatty acids and derivatives thereof (for exampleγ-linolenic acid, linoleic acid, oleic acid), folic acid and derivativesthereof, ubiquinone and ubiquinol and derivatives thereof, vitamin C andderivatives (for example ascorbyl palmitate, magnesium ascorbylphosphate, ascorbyl acetate), tocopherols and derivatives (for examplevitamin E acetate), vitamin A and derivatives (vitamin A palmitate) aswell as conyferyl benzoate of benzoin resin, rutinic acid andderivatives thereof, ferulic acid and derivatives thereof,butylhydroxytoluene, butylhydroxyanisole, nordihydroguaiac resin acid,nordihydroguaiaretic acid, trihydroxybutyrophenone, uric acid andderivatives thereof, mannose and derivatives thereof, zinc andderivatives thereof (for example ZnO, ZnSO.sub.4), selenium andderivatives thereof (for example selenium methionine), stilbenes andderivatives thereof (for example stilbene oxide, trans-stilbene oxide)and those derivatives (salts, esters, ethers, sugars, nucleotides,nucleosides, peptides and lipids) of these named active ingredients,which are suitable according to the invention.

Suitable light stabilisers are, for example, organic UV absorbers fromthe class of 4-aminobenzoic acid and derivatives, salicylic acidderivatives, benzophenone derivatives, dibenzoylmethane derivatives,diphenyl acrylates, 3-imidazol-4-yl acrylic acid and esters thereof,benzofurane derivatives, benzylidene malonate derivatives, polymeric UVabsorbers, containing one or more organosilicon radicals, cinnamic acidderivatives, camphor derivatives, trianilino-s-triazine derivatives,2-hydroxyphenyl benzotriazole derivatives,2-phenylbenzimidazole-5-sulfon-ic acid and salts thereof, anthranilicacid menthyl esters, benzotriazole derivatives.

The following might be named as examples of suitable cooling substances:1-menthol, menthone glycerol acetal, menthyl lactate, substitutedmenthyl-3-carboxylic acid amides (for example menthyl-3-carboxylicacid-N-ethylamide), 2-isopropyl-N,2,3-trimethylbutan-amide, substitutedcyclohexane carboxylic acid amides, 3-menthoxypropane-1,2-diol,2-hydroxyethylmenthyl carbonate, 2-hydroxypropylmenthyl carbonate,N-acetylglycine menthyl ester, menthylhydroxycarboxylic acid esters (forexample menthyl-3-hydroxybutyra-te), monomenthyl succinate2-mercaptocyclodecanone, menthyl-2-pyrrolidin-5-one carboxylate.

The melts obtainable by the process according to the invention are stillflowable such that the melt can be discharged through small openings atfeasible temperatures and not excessive extrusion pressure, withoutleading to undesirable aroma losses. The melt discharged from theextruder enables effective die-face pelletisation to be carried outvirtually without cutting losses. Cutting losses are understood to bethose aroma particles which do not fall within the desired particle sizefraction.

The preferred type of extruder is a twin-screw extruder.

The openings at the extruder exit, through which the melt is delivered,may be of any form and size. Round openings having a diameter of from0.1 to 5 mm, preferably 0.2 to 2.5 mm, in particular preferably 0.3 to1.5 mm, are preferred. Perforated disks are normally used.

The aroma particles obtained have an apparent density of from 0.5 to 1.5kg/1, preferably 0.7 to 0.9 kg/l.

In the present invention a die-face pelletisation of the melt dischargedfrom the extruder in a flowable, still unsolidified state is carried outin the immediate spatial proximity of the extruder exit. For thispurpose the manner in which the comminution is undertaken is immaterial.The comminution may thus take place by means of knives, wires or someother cutting tool. The direction of motion of the cutting tools may bedesigned to be vertical, horizontal or in both directions, as well asrotary.

The die-face pelletisation of the melt according to the inventionenables a homogeneous product having a narrow, regulated particle sizedistribution to be prepared and simultaneously to a large extenteliminates the occurrence of the undesirable dusty fines, confining itto less than 2 wt. %.

For example, the process according to the invention may be carried outin the following stages:

a. Melt the matrix

A suitable dry matrix containing from 30 to 70 wt. % carbohydratepolymers is prepared and is melted in an extruder by heating to 80 to120° C., preferably 90 to 100° C. For this purpose a twin-screw extruderhaving a plurality of temperature zones is preferably used, for examplehaving the following settings: temperature 1^(st) zone 75° C.,temperature 2^(nd) zone 90° C., temperature 3^(rd) zone 40° C.,temperature die 100 to 120° C., depending on pressure and flow rate.

b. Emulsify the aroma into the dry mixture

The aroma, which may contain additionally a suitable emulsifier as wellas other ingredients, is introduced continuously by way of a pump intothe front region of the extruder at a dose of preferably from 1 to 25,for preference 3 to 10 wt. %, with reference to the dry mixture. Theextrusion dies effect the emulsification of the aroma and the optionallypresent further ingredients in the melt.

The melting of the dry materials is controlled by the heating of thehousings and the frictional heat of the rotation of the screws. Asuitable screw configuration regulates the degree of charging and theresidence time of the mixtures in the extruder.

The degree of charging, the residence time, the mixing efficiency, thefrictional heat generated and the material pressure can be influencedwith the aid of the screw speed.

c. Discharge from the extruder

In order to shape the strands downstream of the opening, the melt mustbe cooled. This is preferably effected by blowing cold air in concentricmanner onto the perforated disk. Here, uniform temperature control ofthe opening must be ensured.

A minimum pressure of 20 bar must be produced upstream of the die, inorder to enable delivery to be uniform with no pulsing. The idealpressure range is between 35 and 55 bar. The liquid aroma must not beadded until the cooled region of the extruder, since otherwisebacking-up, or boiling of volatile constituents, may occur.

Experience dictates that the product temperature upstream of the dieshould be between 94 and 105° C. If the temperature is too low theviscosity of the melt, and the material pressure, increases, thuspermitting only low-performance operation. If the temperature is toohigh the emerging strands are too soft and sticky, thus renderingpelletisation impossible.

The dies must be of conical design and have the smoothest possiblesurface within the channels. A coated outer skin increases the life ofthe die plates.

d. Formation of the aroma particles

The comminution of the strands takes place while still in thesolidification phase by means a of die-face pelletisation. For thispurpose, a gas-tight implementation of the die-face pelletisation havingrotating cutting knives is used, which takes place directly at theextruder exit. Infinitely variable control of the die-face pelletisationenables the particle length to be adjusted dependent on the solids flowrate. For a smooth cut, the knife shaft of the pelletiser should runflexibly and be spring-mounted. The knife blades must present a smoothsurface to the die plate on which they bear. The speed of rotation ofthe knives should be between 2500 and 3000 rpm. As a result of the highcutting speeds a cooling effect, necessary for a permanently good cut,is generated by way of the rotation. The knife blades themselves mayhave a metal thickness of from 0.5 to 1.0 mm.

The aromas can normally be released from the aroma particles byhumidity, water, temperature or combinations thereof.

The aroma particles according to the invention can be used, for example,for aromatising foods or oral hygiene products, such as instant beveragepowders, teas, soup or sauce powders, confectionery, chewing-gums,toothpastes, oral gels, chewable tablets or chewable sweets.

The aroma particles according to the invention can be used, for example,for atomatising pharmaceuticals and pharmaceutical formulations, such assweets for sucking, tablets for sucking, chewable sweets, chewabletablets, tablets to be dissolved in water or infusion formulations.

The aroma particles according to the invention can be used, for example,for aromatising consumer articles such as cosmetics, soaps, detergents,washing agents, room fragrancers, hygienic or household products.

EXAMPLES Preparation Examples Example 1 Preparation of Lemon AromaParticles

A suitable carbohydrate mixture is melted in a twin-screw, TO-EX 45-typeextruder from Togum, having nine housing blocks and a plurality ofseparately temperature-controllable zones having the following operatingconditions:

heating temperature 1^(st) zone 75° C. heating temperature 2^(nd) zone90° C. heating temperature 3^(rd) zone 40° C. heating temperature die100 to 120° C., depending on pressure and flow rate product temperatureentering 1^(st) zone room temperature product temperature entering2^(nd) zone 60° C. product temperature entering 3^(rd) zone 120° C.product temperature entering die 110° C. product temperature entering1^(st) zone e.g. 96° C. (90 to 110° C.) screw speed 100 rpm drysubstance flow rate 30 kg/h lemon aroma flow rate 1.8 kg/h

The carbohydrate mixture comprises the raw materials Glucidex IT 47 Wfrom wheat (from Roquette; monosaccharides 0.7%, disaccharides 56.3%,trisaccharides 18.7%, tetrasaccharides 1.8%, oligosaccharides from thepentasaccharides upwards, having a molecular weight of over 1000, 22.5%)as well as Maltodextrin DE 15-19 from wheat (from Cerestar,monosaccharides 0.4%, disaccharides 5.0%, trisaccharides 9.5%,tetrasaccharides 5.0%, pentasaccharides 4.8%, hexasaccharides 11.4%,oligosaccharides from the heptasaccharides upwards 63.9%).

A suitable formulation contains 8340 g Glucidex IT 47 W from wheat, 3600g Maltodextrin DE 15-19 from wheat and 60 g Monomuls (fromGrunau-Illertissen, molecularly distilled monoglyceride based on palmoil, E471). It has a calculated 33.50% content of oligosaccharidesgreater than DP 6. The aroma, to which is added 3% of the emulsifierTween 80 (from ICI, polyoxyethylene-(20)-sorbitan monooleate orpolysorbate 80), is introduced continuously into the front region of theextruder at a dose of, for example, 6%, with reference to the drymixture, by way of a supply by electromechanical reciprocating meteringpump at a pressure of approximately 30 to 35 bar. The extrusion dieseffect the emulsification of the aroma in the melt.

Cold air is blown onto the perforated disk in concentric manner. Here,care must be taken to ensure uniform temperature control, such that nospot cooling occurs. The die-face pelletisation is implemented ingas-tight manner in order to prevent aroma contamination of theenvironment. 3 knives of 0.5 mm sheet steel and a pelletising platehaving 600 drilled holes of nominal diameter Ø1.0 and 1000*Ø0.6 drilledholes on concentric circles are utilised for the preparation of aromaparticles of nominal particle size 1 mm. The die-face pelletisationrotation speed, for adjusting the pellet length, is infinitely variabledependent on the solids flow rate. The pellets obtained here have anapparent density of approx. 0.8 to 0.9 kg/l. Dust and/or oversizedparticles are then removed by a doubledeck sieve having 0.8 mm and 1.25mm sieve sizes. The sieving losses are less than 5% of yield.

Example 2 Preparation of Passion Fruit Aroma Particles

A further suitable formulation having 4740 g Glucidex maize, 3600 gmaltodextrin maize, 1400 g spray-dried glucose from maize, 200 g gumarabic and 60 g Monomuls has a calculated 39.70% content ofoligosaccharides greater than DP 6. The Cerestar spray-dried glucosefrom maize has the trade name C*Dry GL 01934 and comprises 11.5%monosaccharides, 40.1% disaccharides, 21.0% trisaccharides, 8.7%tetrasaccharides, 3.2% pentasaccharides and 1.0% hexasaccharides as wellas 24.5% oligosaccharides from the heptasaccharides upwards. 6% aromawith 2% Tween 80 emulsifier are introduced into the front region of theextruder. The operating conditions of the TO-EX 45 twin-screw extruderare as follows:

2 heating temperature 1^(st) zone 75° C. heating temperature 2^(nd) zone90° C. heating temperature 3^(rd) zone 40° C. heating temperature die100 to 120 C.., depending on pressure and flow rate product temperatureentering 1^(st) zone room temperature product temperature entering2^(nd) zone 60° C. product temperature entering 3^(rd) zone 120° C.product temperature entering die 110° C. product temperature entering1^(st) zone e.g. 96° C. (90 to 110° C.) screw speed 100 rpm drysubstance flow rate 30 kg/h passion fruit aroma flow rate 1.8 kg/h

3 knives of 0.5 mm sheet steel and a pelletising plate having 1000drilled holes of nominal diameter Ø0.6 on concentric circles areutilised for the preparation of aroma particles of nominal particle size0.6 mm. The pellets obtained here have an apparent density of approx.0.8 to 0.9 kg/l. Dust and/or oversized particles are then removed by adoubledeck sieve having 0.5 mm and 1.0 mm sieve sizes. The sievinglosses are less than 5% of yield.

The two Preparation Examples above show embodiments of the invention byway of example. The Maltodextrin DE 15-19 should be regarded ascarbohydrate polymers having an average molecular weight greater than1000, while the two glucose syrups are on average markedly below amolecular weight of 1000. The procedure is transferable to any otherflavours, but also to fragrance oils. Using the same procedure, it isfurthermore possible to prepare larger particle sizes of up to severalmillimetres as well as smaller particle sizes up to 0.3 mm.

Application Examples Example 3 Tea-Bag Tea

Aromatisation of black tea in tea-bags with 3 wt. % lemon aromaparticles (Ø1 mm, length 1 to 2 mm). During storage of the tea, thearoma remains enclosed in the pellet matrix and is not released until,on brewing, the particle matrix is dissolved in hot water.

Example 4 Instant Beverage Powder

Aromatisation of an instant beverage powder mixture comprising 90 wt. %saccharose, 8 wt. % citric acid, 1 wt. % further ingredients (calciumphosphate, ascorbic acid, modified cellulose, colorant) and 1 wt. %yellow-coloured passion fruit aroma particles (Ø0.6 mm) which have beenprepared by the procedure described. The mixture is distinguished byparticularly good stability of the aroma in storage, even at lowparticle size. Because of the small proportion of oxidation-sensitivepassion fruit aroma at the surface of the particles, the occurrence ofoff-flavours (caused by oxidation) is very greatly minimised.

Example 5 Chewing-Gum

Blue-coloured peppermint aroma particles (Ø0.6 mm, length 0.4 mm)prepared by the process described are added to chewing-gum mass. Theparticles create a particular optical effect. The aroma is released inmechanical manner during chewing.

Example 6 Temperature-Controlled Fragrance Release

Uncoloured perfume oil particles (Ø0.6 mm, length 0.4 mm) which havebeen prepared by the process described are added to a heating andcooling plate. The perfume oil is released by heating. The release ofthe perfume oil can be started and stopped repeatedly by a heating andcooling cycle until the perfume oil is completely consumed.

Example 7 Soap

Uncoloured perfume oil particles (Ø0.6 mm, length 0.4 mm) prepared bythe process described are added to a soap. The perfume oil is releasedby dissolution. The release of the perfume oil can be started andstopped repeatedly by a solubilisation and drying until the soap iscompletely consumed.

1. Aroma particles comprising a matrix and an aroma that have beenprepared by extrusion of an aromatised melt followed by die-facepelletisation, wherein the matrix of the particles contains from 20 to80 wt. % carbohydrate polymers having an average molecular weightgreater than
 1000. 2. Aroma particles according to claim 1, wherein thematrix of the particles contains from 30 to 70 wt. % carbohydratepolymers having an average molecular weight greater than
 1000. 3. Aromaparticles according to claim 1, wherein the matrix of the particlescontains from 40 to 60 wt. % carbohydrate polymers having an averagemolecular weight greater than
 1000. 4. Aroma particles according toclaim 1, wherein the matrix of the particles contains an emulsifier. 5.Aroma particles according to claim 4, wherein the matrix containsmonoglycerides in a quantity of from 0.5 to 3 wt. %.
 6. Aroma particlesaccording to claim 1, wherein the matrix of the particles containsglucose.
 7. Aroma particles according to claim 6, wherein the matrixcontains glucose in a quantity of from 0.5 to 5 wt. %.
 8. Aromaparticles according to claim 1, wherein said particles have a glasstransition temperature within the range 30 to 100° C.